I'm in central Illinois and this liner is only 1 year old.....started wrinkling but I'm not sure why I've kept my PH levels around 7.4-7.5 and my FC levels around 3 all summer. A friend of mine who works for a pool store thinks maybe it is the sand we used on the bottom (regular sand) and not masonry sand...he thinks where the sand on the bottom is separating (and it is) it's pulling from the side for compensation. My question is....if I remove my return eyeball to put the plug in will it release this wrinkle and I won't be able to get the liner back up to put the eyeball cover back on or should I just leave the return eyeball in.....we lower water 5-6" below return and water freezes over in winter here. Cannot get the guy (company) who installed the liner to return my emails....View attachment 42999View attachment 43000...